1. Field of the Invention
The present invention relates to materials used in the construction of buildings and other sheets, and custom forms as well as semi-liquid materials such as mortars and plasters.
2. Description of the Related Art
With over 50% of the average landfill mass comprised of paper, and with the growing need to decrease landfill input for obvious reasons, the ability to turn this paper into usable, stable, strong building products is a great advantage.
Many attempts dating back to the early 1900's have been made to develop structural building materials using discarded paper products. While these inventions used discarded paper products or fibrous material, they all relied substantially on other materials to supply the structural strength.
An example of the use of reinforcement elements or strengthening materials in a structure made from fibrous material is U.S. Pat. No. 1,268,929 to Conniff, which uses a reinforcing metallic element to provide additional structural strength to a wood fiber/cement composite material.
U.S. Pat. No. 1,604,097 to Hewlett and U.S. Pat. No. 1,633,702 to Hewlett et al. describe a similar structure where a wall made from a fiber/plaster mixture is reinforced by reinforcing elements made of wire or beams formed by pouring cement into the wall.
U.S. Pat. No. 1,808,562 to Melandri discloses a building block in which a cubic foot of material contains ten pounds of lime, twenty pounds of cement and sixty pounds of fibrous material, thus creating an extremely dense and heavy building product.
U.S. Pat. No. 3,718,536 to Downs et al. combines shredded paper with glass fibers, both of which are compressed using heat and pressure to make a composite board. The heat is necessary to melt thermoplastic material present in the limited range of paper types used in the process so that the thermoplastic material bonds the shredded paper material together.
U.S. Pat. No. 4,060,363 to Nelson discloses a method in which shredded paper is processed under heat and pressure to form paper into blocks to save shipping expenses in recycling. The resultant blocks provide a compact unit for shipping; however, the blocks cannot support a significant load and are manifestly unsuitable for construction applications.
U.S. Pat. No. 4,148,952 to Nelson et al. discloses a similar process in which shredded paper is combined with a glue binder and processed under heat and pressure to form the blocks. Though the binder decreases the tendency of the compressed paper to break up, the glue does not permeate the individual fibers in the paper; rather, it causes the inherently weak individual shreds to adhere to each other; thus, the product will fail under any significant load and cannot be used as a building material.